Need help building business desktop

My name is Jon and I am trying to built desktop computer for my business, The PC is going to be used primarily for data and i take allot of images and store them in the computer. Another important aspect would be that the pc be able to handle multi tasking since I have more than one window open and I work on separate one semantically. I research a lot, I came with the following hardware I would like your opinion as well as your suggestion. For the this PC, I am looking to built a PC with Intel chip : Intel Core i5-2500K Sandy Bridge 3.3GHz (3.7GHz Turbo Boost) 4 x 256KB L2 Cache 6MB L3 Cache LGA 1155 95W Quad-Core Desktop Processor BX80623I52500K, with either 8gig or 16gig?

The memory ram I am considering is CORSAIR Vengeance 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CMZ8GX3M2A1600C9B, or Crucial?!, I like to know which would be a better choice. Regarding power supply Some good brands to look for are: PC Power and Cooling, Enermax, Antec, and Tagan but I couldn’t fined which would be a good choice for me? The motherboard I found ASUS P8P67 PRO (REV 3.0) LGA 1155 Intel P67 SATA 6Gb/s USB 3.0 ATX Intel Motherboard.

As for video card I like to have at least 1 gigabyte of video card I have found EVGA 012-P3-1472-AR GeForce GTX 470 (Fermi) Super Clocked 1280MB 320-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card but Would appreciate a suggestion from you. Finally I found this tower Antec Nine Hundred Two Black Steel ATX Mid Tower Computer Case? Hard drive Western Digital Caviar Black WD1001FALS 1TB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive. For the DVD and cd drive I am not to concern about Sony will do just fine.